EMI and reliability improvement in DC-fed induction motor drives by filtering techniques

This paper presents design issues and realization of a common mode (CM) electromagnetic interference (EMI) filter for a DC-supplied motor drive equipped with an output active CM voltage compensator. The obtained system allows both reliability and EMI of the motor drive to be improved at the same time. In particular, as for reliability, the active CM voltage compensator gives a reduction of the stress on motor bearings; in addition, the input EMI filter, designed taking into account the impedance mismatching between EMI source and receiver in the actual circuit configuration, allows standard limits to be satisfied. Simulation analysis and experimental assessments are given.